class Solution {
public:
    int rob(vector<int>& nums) {
        int n = nums.size();
        return max(nums[0] + rob1(nums, 2, n - 2), rob1(nums, 1, n - 1));
    }
 
    int rob1(vector<int>& nums, int left, int right)
    {   
        if(left > right)
            return 0;
 
        int n = nums.size();
        vector<int> f(n);
        auto g = f;
        f[left] = nums[left]; // 初始化
        for(int i = left + 1; i <= right; ++i) // 填表
        {
            f[i] = g[i - 1] + nums[i];
            g[i] = max(f[i - 1], g[i - 1]);
        }
        return max(f[right], g[right]);
    }
};